'Big Bang Theory' Star Kunal Nayyar Accused of Screwing Agent Out of 'Big Bang' Cash

Ain't no party like a Koothra-party! Especially for "Big Bang Theory" star Kunal Nayyar -- who plays Raj Koothrappali on the show -- because according to a new lawsuit ... he's been living it up big time without paying his agent.Diverse Talent Group…